'Xmas' definitions:

Definition of 'Xmas'

From: WordNet
noun
A Christian holiday celebrating the birth of Christ; a quarter day in England, Wales, and Ireland [syn: Christmas, Christmas Day, Xmas, Dec 25]

Definition of 'Xmas'

From: GCIDE
  • Xmas \X"mas\, n. Christmas; -- an abbreviation for the Christian holiday celebrating the birth of Christ; a quarter day in England, Wales, and Ireland.
  • Syn: Christmas, Christmas Day, Dec 25. [WordNet 1.5]